[PATCH net] neighbour: fix unaligned access to pneigh_entry

From: Qingfang DENG
Date: Wed May 31 2023 - 06:42:30 EST

From: Qingfang DENG <qingfang.deng@xxxxxxxxxxxxxxx>

After the blamed commit, the member key is longer 4-byte aligned. On
platforms that do not support unaligned access, e.g., MIPS32R2 with
unaligned_action set to 2, this will trigger a crash when accessing
an IPv6 pneigh_entry, as the key is cast to an in6_addr pointer.

Align the member to 4 bytes on said platforms.

Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.")
Signed-off-by: Qingfang DENG <qingfang.deng@xxxxxxxxxxxxxxx>
include/net/neighbour.h | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 3fa5774bddac..c0195ed9d111 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -180,7 +180,11 @@ struct pneigh_entry {
netdevice_tracker dev_tracker;
u32 flags;
u8 protocol;
u8 key[];
+ u8 key[] __aligned(4);